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Full-scale study of removal effect on Cyclops of zooplankton with chlorine dioxide

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Journal of Environmental Sciences 2004年第5期16卷 746-750页

作者： LINTao CUIFu-yi LIUDong-mei ANDong SchoolofMunicipalandEnvironmentalEngineering HarbinInstituteofTechnologyHarbin150090China

Cyclops of zooplankton propagated excessively in eutrophic water body and could not be effectively inactivated by the conventional disinfections process like chlorination due to its stronger resistance to oxidation. In this paper, a full-scale study of chlorine dioxide preoxidation cooperating with routine clarification process for Cyclops removal was conducted in a waterworks. The experimental results were compared with that of the existing prechlorination process in several aspects: including the Cyclops removal efficiencies of water samples taken from the outlets of sedimentation tank and sand filter and the security of drinking water and so on. The results showed that chlorine dioxide might be more effective to inactivate Cyclops than chlorine and Cyclops could be thoroughly removed from water by pre-dosing chlorine dioxide process. The GC-MS examination and Ames test further showed that the sort and amount of organic substance in the treated water by chlorine dioxide preoxidation were evidently less than that of prechlorination and the mutagenicity of drinking water treated by pre-dosing chlorine dioxide was substantially reduced compared with prechlorination.

关键词： Cyclops of zooplankton chlorine dioxide chlorine preoxidation water treatment

Improved length of calcium sulfate crystal seeds and whiskers via ball milling and hydration treatment

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Chinese Journal of Chemical Engineering 2024年第7期71卷 102-109页

作者： Yuke Li Yuxin Liu Jizhen Huang yi mei Faculty of Chemical Engineering Kunming University of Science and TechnologyKunming 650500China Yunnan Provincial Key Laboratory of Energy Saving in Phosphorus Chemical Engineering and New Phosphorus Materials Kunming University of Science and TechnologyKunming 650500China

Elucidating the effect of growth periods on the quality of calcium sulfate whiskers(CSWs)prepared from calcium sulfate dihydrate(DH)is ***,crystal seeds and whiskers were prepared from DH in a water–glycerol *** whiskers were obtained from crystal seeds prepared via hydration of DH for 30 s than via ball milling for 5 min followed by hydration for 20 *** attachment of cetyltrimethyl ammonium bromide and glycerol additives to the whisker tops promoted whisker *** whisker sponges exhibited good thermal barrier properties and compression cycle stability.

关键词： Hemihydrate gypsum whisker Hydration Ball milling/hydration Crystal seed Growth process

Effect of pH on binding of pyrene to hydrophobic fractions of dissolved organic matter(DOM) isolated from lake water

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Acta Geochimica 2016年第3期35卷 288-293页

作者： yi mei yingchen Bai Liying Wang State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences State Environmental Protection Key Laboratory for Lake Pollution Control Research Center of Lake EnvironmentChinese Research Academy of Environmental Sciences

In order to better understand the compositional and structural complexity of dissolved organic matter(DOM) macromolecules and provide mechanistic information on the binding of hydrophobic organic contaminants(HOCs) to DOM, we fractionated large amounts of lake water into three hydrophobic DOM-fractions. The variation of the partitioning coef?cients(K_(DOC)) of pyrene at different p H levels was examined by ?orescence quenching titration. Results show that, relative to the more polar acidic DOM-fractions, the hydrophobic neutral fraction exhibits a higher sorption ability to pyrene. Generally, the sorption of pyrene to the three hydrophobic fractions is strongly pH-dependent. The K_(DOC) values of pyrene generally increase with decreasing p H levels, which is especially obvious in the sorption of pyrene to the fulvic acid fractions, suggesting that the binding is controlled by hydrophobic interactions. The mechanisms underlying the binding of pyrene to the hydrophobic fractions were also discussed. Our data are bene?cial to further understanding the binding of HOCs to DOM and how it has been affected,which may result in more accurate predictions of K_(DOC).

关键词：疏水性有机污染物溶解有机物 DOM 酸组分 pH值分离湖水绑定

Experimental study and cellular automata simulation of corrosion behavior of ferritic stainless steel in molten aluminum

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Journal of Iron and Steel Research International 2022年第9期29卷 1485-1494页

作者： Ji-yin Long Tian-tian Zhao mei-yi Yuan yi-tao Yang School of Materials Science and Engineering Shanghai UniversityShanghai 200444China

The corrosion behavior of feritic stainless steel(446)after being immersed in molten Al alloy at 750℃ for 1,2,4,and 8 h has been investigated experimentally and *** microstructure and composition distribution at the corrosion interface were characterized using the optical microscope,scanning electron microscope,and energy dispersive *** results showed that Cr and Si synergistically delay the progress of corrosion at the interface of the intermetallic compounds(IMC).In the early stage of corrosion,Si element was enriched at the interface of IMC1 and IMC2,and the diffusion channels of Al element were occupied by ***,as the corrosion progresses,Cr and Si gradually gather to form a band-like structure and coarsen,causing their hindering effect to be *** the corrosion time increases,the banded structure was further aggregated and coarsened,and the inhibitory effect of Cr and Si elements on corrosion was strongly *** addition,based on the cellular automata dynamics model of reaction-diffusion,the corrosion process of ferritic stainless steel in aluminum alloy melts was *** is demonstrated that if there is no stabilizing effect of Cr element,the thickness of IMC will be doubled.

关键词： Stainless steel Molten Al alloy Intermetallic Diffusion-Cellular automata

Characterizing ship-induced hydrodynamics in a heavy shipping traffic waterway via intensified field measurements

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Water Science and Engineering 2020年第4期13卷 329-338页

作者： Li-lei Mao yi-mei Chen Xin Li Department of Port Waterway and Coastal EngineeringSoutheast UniversityNanjing 211189China

Ship-induced hydrodynamics play an important role in shaping the cross-sectional profile of inland waterways and produce a large amount of pressure on the fluvial *** study aimed at quantifying the characteristics of ship-induced waves and currents in a heavy shipping traffic waterway via intensified field measurements conducted in the Changzhou segment of the Grand Canal,in Jiangsu Province,*** on the processed hydrodynamic data,waves and currents caused by single ships and multiple ships were *** single ships,the shipinduced wave heights estimated with empirical formulas were not consistent with the *** by the loading conditions of barges,the drawdown height was characterized by the ratio of ship speed to its limit *** maximum non-dimensional ship-induced wave height was parameterized by a nonlinear combination of the depth Froude number and a blockage *** multiple ships,when ships closely followed each other or interlaced each other's paths,it was difficult to characterize the superposition of several ship *** magnitudes of current velocities induced by single ships and multiple ships were respectively nine and six times as large as those of natural *** may result in more severe sediment(re)suspension than natural flows.©2020 Hohai *** and hosting by Elsevier *** is an open access article under the CC BY-NC-ND license(http://***/licenses/by-nc-nd/4.0/).

关键词： Ship-induced waves Drawdown Field measurements Current velocity Sediment(re)suspension Grand Canal

Ultrahigh spatiotemporal resolution beam signal reconstruction with bunch phase compensation

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Nuclear Science and Techniques 2024年第5期35卷 99-108页

作者： You-Ming Deng Yong-Bin Leng Xing-yi Xu Jian Chen yi-mei Zhou Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai Synchrotron Radiation Facility Chinese Academy of SciencesShanghai 201204China University of Science and Technology of China Hefei 230026China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

Various electromagnetic signals are excited by the beam in the acceleration and beam-diagnostic elements of a particle *** is important to obtain time-domain waveforms of these signals with high temporal resolution for research,such as the study of beam–cavity interactions and bunch-by-bunch parameter ***,a signal reconstruction algorithm with ultrahigh spatiotemporal resolution and bunch phase compensation based on equivalent sampling is proposed in this *** with traditional equivalent sampling,the use of phase compensation and setting the bunch signal zero-crossing point as the time reference can construct a more accurate reconstructed *** basic principles of the method,simulation,and experimental comparison are also *** on the beam test platform of the Shanghai Synchrotron Radiation Facility(SSRF)and the method of experimental verification,the factors that affect the reconstructed signal quality are analyzed and discussed,including the depth of the sampled data,quantization noise of analog-to-digital converter,beam transverse oscillation,and longitudinal *** results of the beam experiments show that under the user operation conditions of the SSRF,a beam excitation signal with an amplitude uncertainty of 2%can be reconstructed.

关键词： Turn-by-turn bunch phase compensation technique Equivalent sampling Signal reconstruction algorithm Ultrahigh spatiotemporal resolution SSRF

Effects of water chemistry and concentrations of dissolved organic matter on its fluorescence characteristics and molecular conformation

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Chinese Journal Of Geochemistry 2009年第4期28卷 413-420页

作者： mei yi WANG Liying WU Fengchang The State Key Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China The State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Chinese Research Academy of Environmental Sciences Beijing 100012 China

Previous studies showed that water chemistry and concentrations of dissolved organic matter (DOM) could affect its molecular conformation and binding characteristics with hydrophobic organic contaminants (HOCs). However, the conformational change of DOM resultant from water chemistry and concentrations of DOM was not extensively investigated; therefore, the contradictory reports regarding the binding property with HOCs were available in literature. In this study, the effects of ionic strength, pH and DOM concentrations on the fluorescence properties of two humic acids (HA), namely Fluka HA and Amherst HA, were investigated by three-dimensional excitation-emission matrix fluorescence spectroscopy (3DEEM) and steady-state fluorescence polarization (FP) techniques. The results not only corroborated previous observations obtained by other investigators, but revealed some new information about the fluorescence properties and molecular conformation of the humic acids under different water chemistry and DOM concentration conditions, which could shed light on its binding mechanisms and binding properties with HOCs.

关键词：有机物浓度溶解有机质分子构象荧光特性水化学 HOCs 有机污染物 DOM

Fabrication and characterization of anodic oxide films on a Ti-10V-2Fe-3Al titanium alloy

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International Journal of Minerals,Metallurgy and Materials 2009年第1期16卷 96-100页

作者： Jian-hua Liu Jun-lan yi Song-mei Li mei Yu Yong-zhen Xu School of Materials Science and Engineering Beihang University Beijing 100191 China

Anodic oxide films of the titanium alloy Ti-10V-2Fe-3Al in ammonium tartrate electrolyte without hydrofluoric acid or fluoride were fabricated. The morphology, components, and microstructure of the films were characterized by scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and Raman spectroscopy. The results showed that the films were thick, uniform, and nontransparent. Such films exhibited sedimentary morphology, with a thickness of about 3 μm, and the pore diameters of the deposits ranged from several hundred nanometers to 1.5 μm. The films were mainly titanium dioxide. Some coke-like deposits, which may contain or be changed by OH, NH, C-C, C-O, and C=O groups, were doped in the films. The films were mainly amorphous with a small amount of anatase and rutile phase.

关键词： titanium alloys anodic oxide films titanium dioxide pulse current method

Determining beam transverse absolute position by triangulation of multi-electrode signal phase differences

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Nuclear Science and Techniques 2024年第8期35卷 38-47页

作者： Xing Yang Hong‑Shuang Wang yi‑mei Zhou Yong‑Bin Leng Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China University of Science and Technology of China Hefei 230026China

Accurate measurement of the transverse position of a beam is crucial in particle accelerators because it plays a key role in determining the beam *** methods for beam-position measurement rely on the detection of image currents induced on electrodes or narrow-band wake field induced by a beam passing through a cavity-type ***,these methods have *** indirect measurement of multiple parameters is computationally complex,requiring external calibration to determine the system parameters in ***,the utilization of the beam signal information is ***,this study proposes a novel method for measuring the absolute electron beam transverse *** utilizing the geometric relationship between the center position of the measured electron beam and multiple detection electrodes and by analyzing the differences in the arrival times of the beam signals detected by these electrodes,the absolute transverse position of the electron beam crossing the electrode plane can be *** method features absolute position measurement,a position sensitivity coefficient independent of vacuum chamber apertures,and no requirement for a symmetrical detector electrode *** feasibility of this method is validated through numerical simulations and beam experiments.

关键词： Electron beam bunch-by bunch diagnostics Bunch position measurement Triangulation method Bunch phase Bunch-by-bunch Transverse position Pickup signal